Latest OS X version for '07 Mini?

[827538]

A friend of mine just bought a used Mac Mini and has upgraded it with a new HDD and 4GB of RAM, he asked me to make him an OS X install disc but I'm a bit unsure what's the latest version he can put on it? - 2007 Mac Mini.

 

[kboller07]

The 2007 can run OS X Lion but Snow Leopard runs much smoother

 

[illusionx]

07 Mac mini max supported is lion.